The present invention relates to a pipe bending machine. More particularly it relates to a pipe bending machine which has an elongated machine frame, a feeding carriage movable in the region of an upper longitudinal edge of the machine frame and carrying a clamping sleeve which clamps a pipe, a bending table provided at a head end of the machine frame and turnable about a vertical axis as well as supporting a bending template, and a turning arm with a clamping device and a clamping jaw as well as a sliding rail provided in the region of an upper longitudinal edge at the side of the feeding carriage and both cooperating with the bending template.
Pipe bending machines of this type are known in the art. In a known pipe bending machine the bending template is formed as a multilevel template provided with a plurality of bending grooves which are arranged over one another and have with different bending radii for bending pipes, and the claimed jaw has a clamping surface which corresponds to the countour of the bending template. Furthermore, for utilization of one or another bending groove of the bending template, a relative displacement between the feeding carriage with the clamping sleeve and the bending template is performed in a vertical direction and transversely to the longitudinal direction of the machine.
In known pipe bending machines of this type it was proposed to raise and lower the bending template in a vertical direction and simultaneously move the same transversely to the longitudinal direction of the machine frame, while the feeding carriage with the clamping sleeve which carries the pipe to be bent remains movable in direction toward the pipe to be bent, and for bending with the multilevel template does not move transversely to the machine frame or to the pipe to be bent.
In accordance with another known solution the bending head with its drive as well as the bending template remain still, and the feeding carriage with the clamping sleeve which carries the pipe is movable upwardly and downwardly in the vertical direction, and also transversely to the longitudinal direction of the machine frame.
Still a further solution proposes to operate with stationary pipe or pipe movable in an axial direction by the feeding carriage, while the bending head moves transversely to the longitudinal direction of the machine frame, and the bending template is supported inside the movable bending head raisable and lowerable in the vertical direction.
All above proposed solutions have the disadvantage in that they require a high structural expenses. It is difficult to arrange all elements which are needed for driving in the vertical direction and in the direction transverse to the longitudinal direction of the machine frame, and because of great movable masses they must have significant dimensions.